Modular power distribution and drive system

Abstract

A modular drive system for a zero turn radius vehicle having a central gear box that powers a variety of left and right side drive mechanisms, the central gear box having a housing forming a sump, an input shaft, a central drive train with an output generally perpendicular to the input shaft, and a power take off mechanism including a clutch having an output shaft collinear with the input shaft.

What is claimed is: 
     
       1. A modular drive assembly for a zero turn radius vehicle having a prime mover, the modular drive assembly comprising:
 a central gear box comprising:
 a housing forming a sump; 
 an input shaft driven by the prime mover; 
 a drive train within the housing and engaged to and driven by the input shaft; 
 a central output generally perpendicular to the input shaft and driven by the drive train, the central output having a first shaft end accessible from a first side of the housing and a second shaft end accessible from a second side of the housing opposite the first side; and 
 a power take off mechanism having an auxiliary output shaft that is collinear with the input shaft and an electric clutch disposed in the sump to selectively couple the auxiliary output shaft to the input shaft; 
 
 a first variable speed drive having a first drive input shaft connected to the first shaft end of the central output; and 
 a second variable speed drive having a second drive input shaft connected to the second shaft end of the central output. 
 
     
     
       2. The modular drive assembly of  claim 1 , further comprising a pulley fixed to the auxiliary output shaft to drive an implement. 
     
     
       3. The modular drive assembly of  claim 1 , wherein the central output comprises a single shaft. 
     
     
       4. The modular drive assembly of  claim 1 , wherein the first variable speed drive is connected to the first shaft end of the central output by a first coupling and a first intermediate shaft, and the second variable speed drive is connected to the second shaft end of the central output by a second coupling and a second intermediate shaft. 
     
     
       5. A modular drive assembly for a zero turn radius vehicle having a prime mover, the modular drive assembly comprising:
 a central gear box comprising:
 a housing; 
 an input shaft driven by the prime mover; 
 a drive train within the housing and engaged to and driven by the input shaft; 
 a central output generally perpendicular to the input shaft and driven by the drive train, the central output having a first shaft end accessible from a first side of the housing and a second shaft end accessible from a second side of the housing opposite the first side; and 
 a power take off mechanism having an auxiliary output shaft that is collinear with the input shaft and a power take off clutch to selectively couple the auxiliary output shaft to the input shaft; 
 
 a first variable speed drive having a first drive input shaft connected to the first shaft end of the central output; and 
 a second variable speed drive having a second drive input shaft connected to the second shaft end of the central output. 
 
     
     
       6. The modular drive assembly of  claim 5 , wherein the power take off mechanism further comprises a brake to arrest the rotation of the auxiliary output shaft. 
     
     
       7. The modular drive assembly of  claim 5 , wherein the central output comprises a pair of separate, coaxial shafts. 
     
     
       8. The modular drive assembly of  claim 5 , wherein the first and second variable speed drives are each connected to the first shaft end and the second shaft end, respectively, by a coupling and an intermediate shaft. 
     
     
       9. The modular drive assembly of  claim 5 , wherein the drive train is selectably driven by the input shaft. 
     
     
       10. The modular drive assembly of  claim 9 , wherein the drive train is selectably driven by a hydraulic drive train clutch. 
     
     
       11. The modular drive assembly of  claim 10 , wherein the drive train further comprises a gear pump to provide pressurized hydraulic fluid to actuate the drive train clutch. 
     
     
       12. The modular drive assembly of  claim 11 , further comprising a filter used in conjunction with the gear pump to remove debris from the hydraulic fluid. 
     
     
       13. The modular drive assembly of  claim 12 , wherein the filter is screwed on to the housing. 
     
     
       14. The modular drive assembly of  claim 5 , wherein the power take off clutch is a hydraulic clutch, and the drive train further comprises a gear pump to provide pressurized hydraulic fluid to actuate the hydraulic power take off clutch. 
     
     
       15. The modular drive assembly of  claim 5 , wherein the power take off clutch is a hydraulic clutch, and the drive train further comprises a charge pump to provide pressurized hydraulic fluid to actuate the hydraulic power take off clutch. 
     
     
       16. The modular drive assembly of  claim 5 , wherein the input shaft is a hollow tube. 
     
     
       17. The modular drive assembly of  claim 5 , wherein the drive train further comprises a charge pump to provide pressurized hydraulic fluid to actuate a gear train clutch. 
     
     
       18. The modular drive assembly of  claim 5 , wherein the power take off clutch is an electric clutch. 
     
     
       19. A modular drive assembly for a zero turn radius vehicle having a prime mover with an output shaft, the modular drive assembly comprising:
 a central gear box comprising:
 a housing having a top and a bottom; 
 an input shaft formed as a hollow through-shaft accessible from either the top of the housing or the bottom of the housing and adapted to receive the prime mover output shaft; 
 a drive train within the housing and engaged to and driven by the input shaft; 
 a central output generally perpendicular to the input shaft and driven by the drive train, the central output having a first shaft end accessible from a first side of the housing and a second shaft end accessible from a second side of the housing opposite the first side; 
 
 a first variable speed drive having a first drive input shaft connected to the first shaft end of the central output; 
 a second variable speed drive having a second drive input shaft connected to the second shaft end of the central output; 
 wherein the central gear box may be oriented in a first direction with the top of the housing adjacent the prime mover, or inverted in a second direction with the bottom of the housing adjacent the prime mover. 
 
     
     
       20. The modular drive assembly of  claim 19 , further comprising a power take off mechanism having an auxiliary output shaft that is collinear with the input shaft and a power take off clutch to selectively couple the auxiliary output shaft to the input shaft.